Nothing. When grandma was alive it was hard for her to step up into her '06 2500 (she was around 4' 10") because the running boards hug the cab so much, so dad took some metal blocks, drilled holes in them, and dropped the running boards down and moved them out so grandma could actually get her feet on the running boards instead of just her toes. I didn't need that when I took over the '06 so dad took them off and put them on his '09. I'm just too lazy to take the blocks out. I think there's a spare set of blocks somewhere, or at least one or two in the garage somewhere. I think the blocks make the back half stick out more so dad could stand on the boards and reach into the tool box. If that's not what you're talking about then I have no clue.